1. Field of the Invention
The present invention relates to fastening devices for use to fasten a heat sink to a CPU holder and, more particularly, to a heat sink fastening device, which can easily detachably be installed to hold down a heat sink on a holder firmly.
2. Description of the Related Art
Heat sinks are commonly used for dissipating heat from a semiconductor device, for example, a CPU. FIG. 1 illustrates a conventional heat sink fastening device fastened to a CPU holder to hold down a heat sink. This structure of heat sink fastening device comprises two clamping plates. Each clamping plate comprises an angled clamping arm 11 and a vertical clamping arm 12 coupled to one end of the angled clamping arm 11. The clamping arms 11 and 12 each have a respective opposite end terminating in a respective hooked portion 111 or 121 for hooking on a respective hook hole 21 in the CPU holder 2. This structure of heat sink fastening device is still not satisfactory in function because the hooked portions 111 and 121 of the clamping arms 11 and 12 tend to be forced away from the respective hook holes 21 upon a vibration.
The present invention has been accomplished to provide a heat sink fastening device, which eliminates the aforesaid problem. According to one aspect of the present invention, the two clamping plates each having two triangular clamping arms adapted for clamping on a holder to hold down a heat sink on the holder, and two hook wires respectively mounted in respective retaining notches in the triangular clamping arms of the clamping plates to hold down the clamping plates, each hook wire having two smoothly arched supporting portions at the ends and two hooking tips respectively horizontally extended from the smoothly arched supporting portions and respectively hooked in respective through holes in the triangular clamping arms of the clamping plates. According to another aspect of the present invention, the clamping plates each have a finger strip for pressing by hand to disengage the hooked portions of the clamping arms from the respective hook holes of the holder.